exec.lua

lemma = {}

require 'class/FileStream'
require 'read'
require 'eval'
require 'compiled/std'
require 'compiled/compile'
require 'env'
require 'type'


---
-- Execute file f in the global environment.
-- If prompt is not nil, f should be stdin; starts a REPL.
---
function exec(f)
	local done = false
	
	if type(f) == 'string' then
		f = io.open(f, 'r')
		prompt = nil
	end
	
	f = FileStream(f)
	lemma['*in-stream*'] = f

	while not done do
		if prompt then io.write(prompt) end
		
		local t = read(f)                         -- read an expression!
	
		if type(t) ~= 'Error' then
			local val = Vector(eval(t, env))      -- evaluate the expression!
			local err = false
			
			for i = 1, val:length() do
				v = val[i]
				if v == Error'eof' then
					done = true
					f:close()
					return
				elseif type(v) == 'Error' then
					io.stderr:write (f:lines() .. ': ' .. tostring(v) .. '\n')
					err = true
				end
			end
			if prompt and not err then
				io.write';=> ' ; write(Seq.lib.unpack(val)) -- print the value!
			end 
		else
			if t == Error'eof' then
				if prompt then io.write('\n') end
				done = true
				f:close()
				return
			else
				io.stderr:write (f:lines() .. ': ' .. e:string() .. '\n')
				if not prompt then
					done = true
					f:close()
				end
			end
		end
	end                                           -- loop!
end